I think that I would also like you prefer to avoid a face to face confrontation....Maybe try to start by removing the access way up to the stand ......remove the ladder or strap on steps or climbing sticks or screw in steps etc... whatever way you have it rigged up to access the stand.
I also whould make sure that your property is thourghly posted . Im not sure of how the law would work if the land is posted to release you from liability? But figure it couldnt hurt. I also would advise your local law inforcement and Conservation Police of the situation in the case of future dealing with this person or persons.... the more eyes watching the area the better .... Most cowards will run like cockroaches at the sight of light or approaching persons.
Let them know their are eyes watching.
But I still like the pulling the shotgun up the tow rope right in front of them idea... had a good laugh at that one[&:]